688788 has 54 divisors (see below), whose sum is σ = 1872234. Its totient is φ = 213408.

The previous prime is 688783. The next prime is 688799. The reversal of 688788 is 887886.

It can be written as a sum of positive squares in only one way, i.e., 636804 + 51984 = 798^2 + 228^2 .

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 688788.

It is not an unprimeable number, because it can be changed into a prime (688783) by changing a digit.

688788 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 12970 + ... + 13022.

It is an arithmetic number, because the mean of its divisors is an integer number (34671).

2⁶⁸⁸⁷⁸⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688788, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (936117).

688788 is an abundant number, since it is smaller than the sum of its proper divisors (1183446).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

688788 is a wasteful number, since it uses less digits than its factorization.

688788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101 (or 77 counting only the distinct ones).

The product of its digits is 172032, while the sum is 45.

The square root of 688788 is about 829.9325273780. The cubic root of 688788 is about 88.3137902258.

It can be divided in two parts, 68878 and 8, that added together give a palindrome (68886).

The spelling of 688788 in words is "six hundred eighty-eight thousand, seven hundred eighty-eight".